QUICK PLS! What is the pH of a solution with a concentration of 4.2 x 10−5 M H3O+
a. 2.31
b. 4.38
c.5.62
d.6.87

In which layer of earth do most earthauakes occur a_ inner core b_outer core c_mantle d_crust

Working with si (metric) units for each of the following commonly used measurements, indicate its symbol. liter gram milliliter kilogram meter centigram milligram centimeter kilometer second millimeter milliseconds

Structure of the atoms: discovery of the nucleus in 1909i need answering all of these questions